The present disclosure relates to a semiconductor structure, and particularly to a semiconductor structure including semiconductor fins and dielectric filler fins located on a dielectric material layer, and a method for manufacturing the same.
A finFET is field effect transistor including a channel located in a semiconductor fin having a height that is greater than a width. FinFETs employ vertical surfaces of semiconductor fins to effectively increase a device area without increasing the physical layout area of the device. Fin-based devices are compatible with fully depleted mode operation if the lateral width of the fin is thin enough. For these reasons, fin-based devices can be employed in advanced semiconductor chips to provide high performance devices.
Semiconductor fins are not necessarily formed with uniform areal density. Local variations in the density of the semiconductor fins lead to variations in the height of gate structures formed over the semiconductor fins. For example, the height of gate structures formed in regions with a low density of semiconductor fins is less than the height of gate structures formed in regions with a high density of semiconductor fins. Such a difference induces topographical variations in the height of the top surface of a gate level dielectric material layer and subsequently formed metal interconnect structures. Thus, there exists a need for reducing topographical variations in the height of gate level structures.